The present invention relates generally to a cleaning device and more specifically to an improved venturi spray nozzle for surface cleaning devices.
Prior art cleaning and spraying devices generally include an induction principle wherein high velocity air is blown past the opening of a tube which is connected to a source of cleaning fluid to educe the cleaning fluid from the tube and atomize it. A typical example of such a sprayer attached as an accessory to the output of a vacuum cleaner is illustrated in U.S. Pat. No. 1,726,741.
As a further development for use with vacuum cleaners, the source of cleaning fluid was pressurized using the output of the vacuum cleaner and cleaning fluid was positively projected onto the surface to be cleaned. The normal suction operation of the vacuum cleaner is used to remove dirty fluid from the surface to be cleaned. A typical example of such a device is found in U.S. Pat. No. 2,243,935.
In later developments, a specialized cleaning device independent of a vacuum cleaner, but using the same principles, was developed using a gravity feed of droplets of cleaning fluid into a high pressure air stream to be projected onto the surface to be cleaned. These cleaning devices generally included a suction nozzle to remove the dirty fluid from the surface. A typical example is found in U.S. Pat. No. 2,986,764.
The air stream projection type of prior art devices generally have a single outlet which prevents even distribution of the cleaning fluid onto the surface to be cleaned. Those prior art devices which have a plurality of outlets are generally positive pressure liquid systems and do not include any form of venturi or eduction priciple. A typical example is found in U.S. Pat. No. 3,883,301.
Generally, the pure induction systems provide a finely atomized spray which is unsatisfactory for cleaning carpets, for example. The totally pressurized fluid source systems require high pressure pumps or fans to produce the desired projection of the fluid onto the surface other than just depositing it. The gravity feed systems generally provide an atomized spray.
Thus, there exists the need for a cleaning device having a spray nozzle incorporating the advantages of the prior art systems without the disadvantages.
An object of the present invention is to provide a spray nozzle for a cleaning device using a venturi effect.
Another object of the present invention is to uniformly distribute the cleaning fluid onto the surface using a plurality of venturi nozzles.
A further object of the present invention is to provide a spray nozzle of simplified constrution.
An even further object of the present invention is to provide a spray nozzle incorporating induction and positive pressure fluid systems.
These and other objects of the invention are attained by providing a cleaning fluid manifold having a plurality of fingers extending through venturi nozzle channels in an air manifold which encompasses the fluid manifold and fingers. The spray nozzles are positioned to provide a fan shape so as to evenly distribute the spray. The source of pressure pressurizes the air which creates the venturi effect is also used to pressurize the cleaning fluid source.
Pressurizing the sources of cleaning fluid assures even dispensing of the cleaning fluid irrespective of variations in the air flow of the spray nozzle. The air pressure provided to the nozzle is substantially greater than the pressure provided to the cleaning fluid source. The air manifold is comprised of two complementary pieces which include integral supports to maintain the cleaning fluid manifold and its fingers centrally positioned in the air manifold.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.